Sunday, May 5, 2013

This Spring Try Macro Photography


[First Published in the May 2013 edition of The Basic Alternative Newspaper]

Photographers know they can get great photos any time of year. But there’s just something about spring that makes us want to get out there and start taking photos. It’s the time of year when insects and other small creatures first appear and life begins anew. It’s also the time when some shutterbugs wish they knew how to take close-ups and macro photographs. Unfortunately, many of them won’t get the opportunity because they believe it’s just too difficult or expensive. And so they miss out on another great spring. Yes, it’s true. Macro photography can get very technical. And yes, some of the equipment can be quite specialized and expensive. But it doesn’t have to be that way. Chances are, you can get started in macro photography with your existing gear—and a little ingenuity.

So, what is close-up, or macro photography? That’s simple: it’s making the small large. The less demanding area of close-ups generally involves reproduction ratios from 1:20 on up to life size, or 1:1. Likely natural subjects include plants and mushrooms. True macro photography begins at life size and goes up from there. But what does life size mean? Back in the days of 35mm film cameras [anyone remember those?] if you shot an ant that was 5mm long, and the ant’s image on the negative was 5mm, then it was shot life size [1:1]—got it? It’s all about subject size compared to image size. Let’s say we photograph that same 5mm ant again and, this time, its image size is 10mm. Now, we’re shooting at 2X life size or 2:1. Confused? Don’t worry, that’s about as mathematical as we’re going to get. We’re almost ready to talk hardware. But before we do, there’s a critical concept we need to cover—depth of field (DOF).

In macro photography, depth of field is key. Simply put, DOF concerns itself with how much of your subject is in focus. Unfortunately, the more you magnify an image, the less the DOF. If your ant’s antennae are in focus, its body probably isn’t. Depth of field is the greatest limiting factor in macro photography. Within limits, you can control it by adjusting your f-stop. Your f-stop [or aperture] refers to the diameter of the aperture formed by the lens’ shutter blades. The smaller the diameter of the aperture, the larger the numerical value of the f-stop. For example, an aperture of f16 is far smaller than f4. More importantly, the smaller the aperture, the greater the depth of field. Because of this, you’ll rarely shoot a macro subject at less than f8, and a smaller aperture would be even better. Avoid stopping the lens down all the way. That will cause excessive diffraction and degrade your image too much.

Now that we’ve covered the basic concepts, how to begin? That depends on what you have to work with. At this point, owners of fixed-lens point and shoots might look askance at their rudimentary cameras, but they’d be mistaken. Not only do most point and shoots have a “macro” mode, by their very design these modest cameras have a built in advantage. That’s because aperture isn’t the only factor that determines depth of field. The area of the negative [film] or sensor [digital] in a camera also helps determine depth of field. The sensors in digital cameras come in a variety of sizes. Don’t worry about what they’re called. What’s important to know is this: if everything else is equal, the smaller the sensor area, the greater the depth of field. So, the person armed with a digital point and shoot and its small sensor will enjoy an advantage in depth of field as compared to someone with a fancier camera with a larger sensor. If they are using lenses of equivalent focal length, the photographer with the point and shoot will have more of his ant in focus. So, if you’ve got a simple camera don’t despair, just go for it.

Even if they do have a camera with interchangeable lens, some photographers don’t own a macro lens. What to do? There are several ways to solve this problem. The simplest approach involves the use of what are called diopters, or supplementary lens. These may be thought of as magnifying glasses that screw on the front of your lens just like a filter. They come singly or in a set. This is a very inexpensive means of gaining magnification but remember, anything you place in front of your lens will degrade the image to some extent. It’s just a matter of striking a balance between magnification and image quality. Try different combinations on your lens and study the results. You’ll soon find what works best for you in any given situation. Diopters also work with point and shoots provided they are available in the correct size.

So, diopters don’t do anything for you? Or maybe you want more magnification? What else can be done with the gear at hand? Another trick that surprises those new to macro photography is the idea of reversing your lens on the camera body with an inexpensive “reversing” ring. That’s right; take the photo with the lens on backwards! Be forewarned, the zoom kit lens so common today rarely work well due to their indifferent optical quality. Fortunately, an inexpensive alternative is probably sitting in your camera bag: the standard 50mm lens. Back in the days of film [around the last ice age], most new cameras sold came equipped with a 50mm, and nothing else. Because of its ubiquity, the 50mm lens is generally not only inexpensive but optically superb as well. Turn it around and you’re instantly shooting at life size (1:1).

You’ll lose auto focus, but don’t worry. Because of depth of field issues, macro is a manual focus game. The DOF is just too shallow to rely upon auto focus. That brings up another point. To use the reverse lens technique, you’ll need a camera that allows you to select a “shoot without lens” option. Otherwise, the camera won’t function. Once “shoot without lens” is selected, just set the camera on aperture priority and it will select the appropriate shutter speed.

Because we’re using manual focus, it might be time to dust off those old lens you [or your parents] have gathering dust because you don’t shoot film anymore. If you use a Canon or one of the micro four-thirds digital cameras, inexpensive adapters can be purchased that allow you to use practically any legacy lens. Even old enlarger lens can be used and are superb for macro due to their optical quality. Because of the flange distance—the distance from the back of the lens element to the sensor plane—Nikons aren’t quite as flexible in this regard.

Besides these techniques, there are a host of other options. It just depends on how elaborate you want to get. For instance, you could try lens stacking, by connecting a shorter focal length lens backwards in front of another lens with an inexpensive “macro coupling” ring. Or you might experiment with extension tubes or teleconverters. That’s the beauty of macrophotography; it’s limited only by your imagination. But remember, for the most part, these more involved techniques are used to obtain higher magnification.

Sounds great, right? The whole idea behind shooting macro is enlarging the subject, so the more the merrier. Unfortunately, you’ll soon find that there are definite limits to what can be accomplished with a hand-held camera. Because of the extremely limited depth of field, 2X is probably the upper limit, even for experienced macro photographers. You could use a tripod—and you should whenever possible—but have you ever tried chasing a butterfly across a field while dragging a camera on a tripod?

Once you start taking macro photographs, you’ll soon find that trying to hold still and keep the subject in focus is enough to drive you crazy. As in target shooting, you have to learn to control your breathing and squeeze off the shot. Whatever you do, don’t rack the focus in and out. Focus the lens at the closest distance [or desired image magnification] and then lean your body in or out to achieve focus. As in photographing big game, you must get the eyes in focus. If they aren’t sharp, it’s a deal breaker. Don’t be surprised if you don’t have too much luck initially. In fact, it’s not uncommon to spend an afternoon shooting only to discover you have little to show for your efforts. If you get a couple of keepers, you’ve had a good day.

Because of the small apertures used for these shots, there never seems to be enough light. This can be a real problem with insects on the move. The quivering of a moth’s antennae or the buzzing of a bee are enough to blur the shot. That’s why it’s good to use a flash when available to stop the motion. Although highly specialized macro flashes are available, they can be quite expensive and are often unnecessary. Instead, why not try the flash you already have? If your flash has a cord, try rigging it out at the end of your lens and off to one side. This will create a modeling effect and emphasize the depth and texture of your subject. Even if you don’t own a flash, an inexpensive LED light carefully positioned can assist you in focusing.

Macro photography doesn’t have to be complicated or expensive. With a little know-how, you can make the gear you already own work for you. The important thing is to refine your technique while gaining experience in the field. Study your subjects and the images you take will improve exponentially. Once you learn how to use your equipment to its full potential you can think about upgrades. In the meantime, it’s spring—what are you waiting for? 

No comments: